import { BadGatewayException, Injectable, Logger } from "@nestjs/common";
import { HttpService } from "@nestjs/axios";
import { AxiosError } from "axios";
import { firstValueFrom } from "rxjs";
import {
    InitiatePaymentRequest,
    PaymentIntentSnapshot,
    PaymentReferenceType,
    PaymentService,
} from "@edr/types";

/**
 * Thin HTTP client for the payment microservice (apps/edr-payment-api).
 * Domain validation stays in the freight API; provider calls, intents,
 * and webhooks live in the payment service.
 */
@Injectable()
export class PaymentClientService {
    private readonly logger = new Logger(PaymentClientService.name);
    private readonly baseUrl = (
        // process.env.PAYMENT_API_URL ??
         "https://paymentcallback.triaplc.com"
        // "http://localhost:3003"
    ).replace(/\/$/, "");
    private readonly serviceToken = process.env.SERVICE_AUTH_TOKEN ?? "";

    constructor(private readonly http: HttpService) { }

    /** POST /payments/initiate — idempotent per (service, referenceType, referenceId). */
    async initiate(request: InitiatePaymentRequest): Promise<PaymentIntentSnapshot> {
        return this.call("POST", "/payments/initiate", request);
    }

    /** GET /payments/intents?… — active intent by domain reference; null when none exists. */
    async getIntentByReference(
        referenceType: PaymentReferenceType,
        referenceId: string,
    ): Promise<PaymentIntentSnapshot | null> {
        const query = new URLSearchParams({
            service: PaymentService.FREIGHT,
            referenceType,
            referenceId,
        });
        try {
            return await this.call("GET", `/payments/intents?${query.toString()}`);
        } catch (err) {
            if (err instanceof AxiosError && err.response?.status === 404) return null;
            throw err;
        }
    }

    private async call<T>(method: "GET" | "POST", path: string, body?: unknown): Promise<T> {
        const url = `${this.baseUrl}${path}`;
        try {
            const response = await firstValueFrom(
                this.http.request<T>({
                    method,
                    url,
                    data: body,
                    headers: this.serviceToken
                        ? { "x-service-token": this.serviceToken }
                        : {},
                }),
            );
            return response.data;
        } catch (err) {
            if (err instanceof AxiosError && err.response) {
                if (err.response.status === 404) throw err;
                const detail =
                    (err.response.data as { message?: string | string[] })?.message ??
                    err.message;
                this.logger.error(
                    `payment service ${method} ${path} → ${err.response.status}: ${detail}`,
                );
                throw new BadGatewayException(`Payment service error: ${detail}`);
            }
            const message = err instanceof Error && err.message ? err.message : String(err);
            this.logger.error(`payment service unreachable (${method} ${path}): ${message}`);
            throw new BadGatewayException("Payment service unreachable");
        }
    }
}